Polysiloxanes containing fluoroalkylaminoalkyl groups

ABSTRACT

This specification describes polysilsesquioxanes of the general formula

ite States Patent aszeldine et al.

l lMarch 13, 1973 POLYSILOXANES CONTAINING FLUOROALKYLAMINOALKYL GROUPSand Northern Ireland, London, England Filed: Nov. 12, 1970 Appl. No.:89,081

Assignee:

Foreign Application Priority Data Nov. 12, 1969 Great Britain..55,38l/69 [1.8. CI. ...260/46.5 E, 260/465 G, 260/4482 N Int. Cl...C08f 11/04 Field of Search ..260/46.5 E, 46.5 G, 448.2 N

[56] References Cited UNITED STATES PATENTS 3,033,815 5/1962 Pike et al..260/46.5

Primary Examiner-Donald E Czaja Assistant Examiner-Melvyn l. MarquisAttorney-Stevens, Davis, Miller & Mosher [57] ABSTRACT Thisspecification describes polysilsesquioxanes of the general formula whereR is a fully fluorinated lower alkyl group and x has the value of 20 to50 and polysiloxanes of general formula where R is a fully fluorinatedlower alkyl group, m is two or three, R is lower alkyl group and y hasthe value 3 to 16. The preparation of these polymers is also described.

6 Claims, No Drawings POLYSILOXANES CONTAINING FLUOROALKYLAMINOALKYLGROUPS The present invention is concerned with novel substituted silanesand with polysiloxanes which are obtained by hydrolysis and condensationof such silanes.

In accordance with the present invention there is provided a novelsubstituted silane of the formula:

F)2 2)m' 3n n G) where R is a fully fluorinated lower alkyl group, R isa lower alkyl group, X is a halogen, excluding fluorine, m is two orthree, and n is two or three.

In the present specification the term lower alkyl group is used to meana straight or branched chain alkyl group containing less than six carbonatoms.

In preferred silanes of the present invention R is trifluoromethyl, R ismethyl and X is chlorine.

The novel silanes of the present invention are readily obtained by freeradical or catalyzed addition of an appropriate silane to a suitableolefin.

In accordance with one aspect of the present invention a process for theproduction of a silane having Formula (l) above includes the steps ofreacting a silane having the formula:

SiHR X wherein R, X and n are as hereinbefore defined, and an olefin ofthe formula:

(RF)2N (CH2)9 CH=CH2 wherein R is as hereinbefore defined and p is zeroor one. The reaction may be carried out by heating, preferably in thepresence of a catalyst such as hexachloroplatinic acid, in a sealed tubefor a time of up to 60 hours at a temperature in the range 60 to 150C.The time of reaction and temperature are interdependent, highertemperatures permitting shorter reaction times. Alternatively thereaction may be carried out under the influence of ultra-violet lightand the photochemical reaction is conveniently carried out by sealingthe reactants in a silica tube. The period of time for which irradiationis carried out depends upon the strength of the ultra-violet source andupon the amount of reactants taking part in the reaction.

The novel substituted silanes of Formula (I) are readily hydrolyzed andheating under reflux in wet ether has been found to convert the silanesof Formula (I) wherein X is halogen to the corresponding silanols,wherein X is OH. These silanols are not stable under these reactionconditions and undergo further reaction by condensation topolysiloxanes. This may be assisted by acids or bases.

In accordance with a feature of the present invention there is provideda polysilsesquioxane having the general formula:

{tRnzN-cuz-c z-siord. w wherein R is as hereinbefore defined and x is aninteger and may have a value of to 50 units.

In accordance with an aspect of the invention a process for theproduction of a polysilsesquioxane of Formula (IV) comprises subjectinga silane of Formula (1) above wherein X is Cl, m is 2 and n is 3 to acondensation reaction under the influence of acid or base. Theparticular polymer obtained is governed by the condensation conditionsused. For example condensation under the influence of a 2:1 molarmixture of 2-ethylhexoic acid and l,l,3,3,-tetramethyl guanidine resultsin a solid polysilsesquioxane in which x is 6 and which may be sublimedin vacuo, whereas condensation in the presence of aqueous hydrochloricacid in toluence solution followed by heat treatment of the crudepolymer at 200C leads to a liquid polysilsesquioxane wherein x isgreater than 20 and which is hydrolytically stable in the presence ofacids and bases at temperatures up to at least about 160C.

In accordance with a further feature of the present invention there isprovided a polysiloxane having the general formula:

{(RF .N-(cH2)..s R v wherein R R, and m are as hereinbefore defined andy is three to sixteen and the product may be cyclic or linear.

In accordance with a further aspect of the invention a process for theproduction of a polysiloxane of Formula (V) as aforesaid comprisessubjecting a silane of Formula (1) above wherein R R and m are ashereinbefore defined and X is cl and n is 2 to hydrolysis andcondensation. The particular products obtained depend upon theconditions chosen. In particular trimers of Formula (V) wherein y is 3may be obtained and by further treatment may be converted topolysiloxanes of higher molecular weight.

In accordance with yet another aspect of the present invention a processfor the production of a polysiloxane of Formula (V) comprisestreating acyclic trimer of Formula (V) wherein y is three with an alkali metalhydroxide followed by heating at a temperature broadly in the region ofto 200C.

Polysilsesquioxanes and polysiloxanes of the present invention have goodthermal stability in vacuo, comparable in many instances, for example,where R is CF;,, to the known polysiloxanes in which the (CF N. CH .Cl-lgroup isreplaced by the CF .CH .CH group, and they also resist attack byacids and bases.

The silanes, polysilsesquioxanes and polysiloxanes of the presentinvention may be used thermally stable hydraulic fluids or as acidand/or base resistant thermally stable elastomers or sealants.

There will now be described by way of example only the production ofthree typical substituted silanes of Formula I above and the hydrolysisand condensation of such silanes to produce polymers of Formulas (IV)and (V) above.

In the following examples reactants and products were manipulated, wherepossible, in a conventional vacuum system to avoid contamination withair or moisture. Photochemical reactions were carried out at a distanceof ca. 20 cm. from a l-lanovia 8.500 lamp. Products were separatedeither by repeated fractional distillation in vacuo or bypreparative-scale gas-liquid chromatography (Perkin-Elmer 1 16, 154B, or451 Fraktometers). The identities of products were established bymolecular weight determination (Regnaults method), elemental analysis,infra-red spectroscopy (Perkin-Elmer 21 instrument with sodium chlorideoptics), nuclear magnetic resonance spectroscopy (Perkin-Elmer R l Ospectrometer operating at 56.46 MHz for 19p and 60.0 MHz for 1 massspectrometry (A.E.l. MS/2H instrument with a resolution of 1 in 700),and gas-liquid chromatography.

The NN-bistrifluoromethylvinylamine used in the following examples wasprepared as described by Alexander, Haszeldine, Newlands and Tipping inJ. Chem. Soc. (C) 1968, 796 and theNN-bistrifluoromethylprop-2-enylamine as described in Example 1.

1n Examples 2, 3 and 4 the production of three substituted silanes asdisclosed in formula (I) above is set forth; in Example 2, R is CF m is2, n is 3 and X is chlorine; in Example 3, R is CF m is 2, R is Me, n is2 and X is chlorine; and in Example 4, R is CF m is 3, R is Me, n is 2and X is chlorine.

EXAMPLE I N-Bromobistrifluoromethylamine (3.00 g., 12.93 mmoles) andallyl chloride (1.20 g., 15.53 mmoles) were rapidly vaporized in vacuointo a Pyrex bulb (5 1.) and exposed to daylight for three hours. Thevolatile products were fractionated in vacuo to give (i) a mixture (3.22g., 10.45 mmoles, 81 percent) (Found: C, 19.7; H, 1.7; N, 4.8. Calc. forC -,H BrC1F N: C,l9.6; H, 1.6; N, 4.5 percent), b.p. 148/750 mm. of2-bromo- 3-ch1oro-NN-bistrifluoromethylpropylamine (2.90 g., 9.40mmoles, 73%) and 1-bromomethyl-Z-chloro-NN- bistrifluoromethylethylamine(0.32 g., 1.05 mmoles, 8%), which could not be separated by distillationor by gas liquid chromatography and was identified by nuclear magneticresonance spectroscopy, (ii) unchanged allyl chloride (0.18 g., 2.40mmoles, 16% recovered), and (iii) a mixture (0.32g., 2.28 mmoles, 18%;M, 140) of NN-bistrifluoromethylamine and perfiuoro(2-azapropene).

A mixture (3.30 g., 10.69 mmoles) of 2-bromo-3-chloro-NN-bistrifluoromethylpropylamine (2.97 g., 9.62 mmoles, 90%) and1 -bromomethyl-2-chloro-NN- bistrifluoromethylethylamine (0.33 g., 1.07mmoles, (product (i) above) was slowly added during 30 minutes to astirred suspension of activated zinc dust (6.0 g.) in refluxing ethanol(8 ml.) and the resulting mixture refluxed for one hour. The volatileproducts were collected in traps cooled to 78, fractionated in vacuo andidentified as propene (0.07 g., 1.67 mmoles, 16%) andNN-bistrifluoromethylprop-Z-enylamine (1.40 g., 7.25 mmoles, 80% basedon major reactant isomer) (Found: C, 31.2; H, 2.6; N, 7.1%; M, 190. C HF N requires C, 31.1; H, 2.7; N, 7.2%; M, 193). b.p. 48/750 mm.(Siwoloboff). infra-red spectral bands at 3.22w, 3.29w, 3.32w, 3.37w,3.45w, 6.06w, 6.87m, 7.38vs, 7.54vs, 8.16vs, 8.48vs, 8.70w, 9.09w,9.85m, 10.10s, 10.70m, 12.58m, 13.25m, 13.895, 14.29s, and 15.38mp..

EXAMPLE 2 Method 1 A mixture of NN-bistrifluoromethylvinylamine (3.47g., 19.4 mmoles) and trichlorosilane (3.94 g., 29.1 mmoles) was sealedin a silica ampoule (300 ml.) and irradiated during 40 hours while beingshaken and gave (i) unchanged vinylamine (0.19 g., 1.4 mmoles, 7 percentrecovered), (ii) unchanged trichloro-silane 1.43 g., 10.6 mmoles), and(iii) Z-NN-bistrifluoromethylaminoethyltrichlorosilane (5.65 g., 18.0

mmoles, 100%) (Found: C, 15.3; H, 1.6; N, 4.5%.

C H Cl F6NSi requires C, 15.6; H, 1.3; N,4.5%),b.p. 134 (isoteniscope);main infra-red spectral bands at 3.45w, 6.79m, 7.23s, 7.49s, 7.78s,8.05w, 8.59s, 9.14m, 9.90w, 10.25m, 11.21m, 12.65m, 13.15w and13.8711'1/L.

Method 2 Dichloromethylsilane (22.80 g., 0.200 mole), NN-bistrifluoromethylvinylamine (25.10 g., 0.140 mole), andhexachloro-platinic acid (0.10 g.), sealed in a Pyrex ampoule (ca. 300ml.), heated at 100 for 48 hours, and the products fractionated invacuo, gave 2- (NN-bistrifluoromethylamino)ethyldichloromethylsilane(37.2 g., 0.127 mole, 97%), unchanged dichloromethylsilane (8.09 g.,0.071 mole, 35% recovered), and unchanged olefin (1.61 g., 9.00 mmoles,6% recovered).

EXAMPLE 3 A mixture of NN-bistrifluoromethylvinylamine (4.40 g., 24.8mmoles) and dichloromethylsilane (4.29 g., 37.3 mmoles) was sealed in asilica ampoule (300 ml.) and irradiated during 48 hours while beingshaken and gave unchanged dichloromethylsilane (1.43 g., 12.4 mmoles,33% recovered; M, 114) and2-(NN-bistrifluoromethylamino)ethyldichloromethylsilane (7.29 g., 24.8mmoles, 10%) (Found: C, 20.5; H, 2.5; N, 5.0; Cl, 23.9%. C H-,Cl F NSi-requires C, 20.4; H, 2.4; N, 4.8; Cl 24.1%), b.p. 142 (isoteniscope);main infrared spectral bands at 3.40w, 3.45w, 6.79m, 7.255, 7.545,7.78s, 7.90s, 8.70s, 9.19m, 9.35m, 9.90m, 10.27s, 11.18s, 12.11s,12.30s, 12.65s, 13.30m, 13.72m, and l4.35mp..

EXAMPLE 4 Dichloromethylsilane (1.77 g., 15.54 mmoles), NN-Bistrifiuoro-methylprop-2-enylamine. (1.50 g., 7.77 mmoles) andhexachloro-platinic acid (0.01 g.) were sealed in a Pyrex ampoule,heated at for 24 hours and the products fractionated in vacuo, to givei. 3-(NN-bistrifluoromethylamino)propyldichl oromethylsilane (2.03'g.,6.61 mmoles, 96%) (Found: C, 23.6; H, 3.1; N, 4.7. C H CI F NSi requiresC, 23.5; H, 2.9; N, 4.6%), b.p. 163/769 mm. (Siwoloboff), infra-redspectral bands at 3.36w, 3.38w, 3.44w, 3.47w, 6.83w, 7.25s, 7.54s,8.03s, 8.70s, 9.17m, 9.52w, 9.90m, 10.20m, 10.64w, 10.99w, 11.14w,12.09m, 12.30m, 12.62m, 13.33w, and l4.49mp.,

ii. unchanged dichloromethylsilane (1.02 g., 8.84 mmoles, 56 percentrecovered), and

iii. unchanged olefin (0.18 g., 0.92 mmole, 11 percent recovered).

EXAMPLE 5 This example describes the hydrolysis and condensation of thesilane produced in Example 2 to give polysilsesquioxane, by threedifferent methods.

Method 1 Water (2.0 g.) was added to2-(NN-bistrifluoromethylamino)ethyltrichlorosilane (1.35 g., 4.3 mmoles)in diethyl ether (5 m1.) and the mixture refluxed during 1 hour. Theether and water were then removed in vacuo to give a viscous liquid(0.95 g., 4.1 mmoles, percent yield calculated as polysilsesquioxane)the infra-red spectrum of which indicated the presence of a considerableamount of silane] (broad band at 3.0p.). The liquid was then heated invacuo as follows: 2 hr. at 2 hr. at 2 hr. at 200; 2 hr. at 350. Aninfra-red spectrum was run after each 2 hour period and only after thefinal 2 hr. at 350 were OH groups shown to be absent. The final productwas a viscous liquid identified as poly-[2-(NN-bistrifluoromethylamino)ethylsilsesquioxane](0.92 g., 4.0 mmoles, 92%) (Found: C, 20.6; H, 1.7;N, 5.9%, C H ab6NO Si requires C, 20.7; H, 1.7; N, 6.0%). Method 22-(NN-Bistrifluoromethylamino)ethyltrichlorosilane (2.80 g., 9.0 mmoles)was dissolved in toluene ml.) and treated with hydrochloric acid (3%w/v, 10 ml.) and the mixture was refluxed during 5 hours. The tolueneand water were removed in vacuo and the liquid product was heated invacuo at 200 (4 hour) to give the polysilsesquioxane (1.90 g., 8.2mmoles, 91%) the infra-red spectrum of which showed only a slightabsorption at 3.011. but which was otherwise spectroscopically identicalwith the material prepared by Method 1. Method 3.

Water (3.0 g.) was added to2-(NN-Bistrifluoromethylamino)ethyltrichlorosilane (6.23 g., 19.8mmoles) in diethyl ether (10 ml.) and the mixture was refluxed during 1hour. The ether was displaced by toluene .and the water removed byazeotropic distillation with toluene. The resultant viscous liquid wastreated with a 2:1 molar mixture of 2-ethylhexoic acid and1,1,3,3-tetramethylguanidine dissolved in an equimolar weight of toluene(0.047 g.) and the mixture was refluxed (5.5 hours) using an azeotropetrap. The precipitated solid was washed several times with boilingtoluene to remove any catalyst and the resultant product was then heatedat 100 in vacuo (2 hr.) to give a crystalline solid (4.32 g., 18.6mmoles, 94%) which, when purified by sublimation in vacuo, gave material(4.15 g., 17.8 mmoles 90%) (Found: C, 20.7; H, 2.0; N, 5.9; F, 48.8%; M,(by osmometry), l425. Calc. for C 4H24F3 N 09Sl IC,20.7; H, N,6.0; M,1392);main infra red spectral bands at 6.78m, 7.23s, 7.50s, 7.76s,8.40-9.20vs (broad), 9.91m, 10.27m, 11.17m, 12.36m, 12.83w and 14.42m(broad)p. possibly a cyclic hexamer (11).

The liquid polysilsesquioxane product by Methods 1 and 2 hasconsiderable hydrolytic stability as is shown by its recovery unchangedfrom the following treatments (a) concentrated sulphuric acid at 100(during 1 hour) (b) syrupy phosphoric acid at 160 during 1% hours (0)methanol and aqueous hydrochloric acid under reflux during 4 hours ((1)powdered, dry sodium hydroxide at 100 during one-half hour and (e) 2Maqueous sodium hydroxide at 100 during one-half hour.

The polysilsesquioxane was slightly charred by heating with concentratedsulphuric acid at 150C during 1 hour.

EXAMPLE 6 This example describes the hydrolysis and condensation of thesilane produced in Example 3 to give polysiloxanes by three methods. Thethird method results in cyclic trisiloxane.

Method 1 Diethyl ether (10 ml.) saturated with water was added to2-(NN-bistrifluoromethylamino)ethyldichlo romethylsilane (0.95 g., 3.23mmoles) in diethyl ether (5 ml.) and the mixture was refluxed during 2hours. The ether and water were removed by distillation and the liquidproduct was heated at 200 in vacuo during 2 hours, after which timeinfra-red examination showed that OH groups were absent. The resultantoil was identified aspoly-[2-(NN-bistrifluoromethylamino)ethylmethylsiloxane] (0.75 g., 3.1mmoles 97%)(Found: C, 24.8; H, 2.9; N, 6.1%. C H F NOSi requires C,25.1; H, 2.9; N, 5.9%) main infra-red spectral bands at 3.33m, 3.39w,4.60w, 4.75w, 6.44w, 6.77s, 7.00s, 7.22vs, 7.50vs, 7.76vs, 7.87vs,8.30s, 8.70s, (broad), 9.25-9-50s (broad) (cyclic tetramer, highercyclics, and linear polymer; Si- O-Si), 9.86vs (cyclic trimer Si-O-Si),10.25s, 11.13s, 12.46s (broad) 13.08m, 14.80w and 14.43s p.. Method 2Diethyl ether ml.) saturated with water was added to2-(NN-bistrifluoromethylamino)ethyldichlo romethysilane (7.24 g., 24.6mmoles) in diethyl ether (20 m1.) and the mixture was refluxed during 2hours.

The ether was distilled off and the water was removed by azeotropicdistillation with toluene. The excess toluene was then removed bydistillation. The resultant polysiloxane (5.20 g., 21.4 mmoles, 87%)(Found: M, (by osmometry), 962.Calc. for C H F N O Si M, 956) had aninfra-red spectrum comparable to that of the material prepared by Method1 (except for the presence of a very strong band at 9.2811. (cyclictetramer; Si-O-Si) rather than the broad absorption at 9.25-9.50 p.) andwas more mobile. When distilled in vacuo the polysiloxane could not beseparated into trimer, tetramer etc. fractions.

Method 3 2-(NN-bistrifluoromethylamino)ethyldichlo romethyl-silane(30.00 g., 0.101 mole) was slowly added (30 min.) to a stirred, aqueoussolution of potas sium hydroxide (4 M, ml.) at a rate sufficient tomaintain a temperature of 5060. After the silane addition was completed,the mixture was stirred at 60 for two hours and the organic componentwas extracted with ether 2 X 50 ml.). The ethereal extract was dried(MgSO and the ether removed to afford viscous poly-[2-(NN-bistrifluoromethylamino)-ethylmethylsiloxane] hydrolysate 19.60g., 82%).

The crude hydrolysate (36.0 g.) was distilled from dry, powderedpotassium hydroxide (0.36 g.) under reduced pressure (6.0 cm.) throughan Ernst Haage spinning-band column (heated length 100 cm., internaldiameter 6 mm.) with the column jacket maintained at ca. 15 below theboiling point of the fraction.

The following fractions were obtained.

i. A fraction (11.8 g., 33%), b.p. 100-175/6.0 cm. (mainly 100-135)considered to be a mixture of unidentified breakdown products containinga small amount of the cyclic trisiloxane with an infra-red spectral bandat 9.75 p.).

ii. A fraction (19.8 g., 0.028 mole, 55%) (Found: C, 24.6; H, 3.2%; M,705. C,,,H F N O Si requires C, 25.1; H, 2.9%; M, 717), b.p. ca. /6.0cm., which was identified as1,3,5-trimethy1-l,3,5-tri-(3-NN-bistrifluoromethylaminopropyl)cyclotrisiloxane,main infra-red spectral bands at 3.36m, 3.39w, 3.43m, 6.78m, 7.24vs,7.52vs, 7.75vs, 7.88vs, 8.00m, 8.70vs, 9.19s and 9.75s, 10.17s, 10.705,10.75w, 11.20m, 11.4lw, 12.45s, 13.11m, 13.90w and 14.42mp..

iii. A viscous liquid (ca. 4g.), b.p. 175/6.0 cm. remained in thestill-pot.

The cyclotrisiloxane was shown by g.l.c. (2m. silicone SE30 column at170C) to be slightly impure and a pure sample (Found: C, 25.1; H, 3.1;N, 5.8; F, 47.7.C, H F, N O Si requires C, 25.1; H, 2.9; H. 5.9; F,47.7%) was separated by g.l.c.

EXAMPLE 7 This example described the polymerization of the cyclictrisiloxane obtained by Method 3 in Example 6.

1,3,5-Trimethyl-l,3,5-tri(3-NN-bistrifluoromethylaminopropyl)-cycltrisiloxane (5.00 g.,7.07 mmoles) was treated with dried, powdered potassium hydroxide (0.2mole under a nitrogen atmosphere. The mixture was then heated at 150Cfor 6 hours and yielded a polysiloxane (Found M, 3990. Calc. for (Cl-l-,F NOSi) M, 3956).

EXAMPLE 8 A stirred sample of pure 1,3,5-trimethyl-1,3,5-tri(3-NN-bistrifluoromethylaminopropyl)cyclotrisiloxane (0.30g.) was heated to150C in vacuo and anhydrous potassium hydroxide flour (0.003g) was addedin vacuo. The mixture was kept at 150C for 10 min., cooled, and tracesof unreacted cyclotrisiloxane removed, to afford a polysiloxane (0.27g.,90%) as a slightly opaque gum of high molecular weight.

We claim: 1. As a composition of matter a polysilsesquioxane having thegeneral formula:

where R, is a fully fluorinated lower alkyl group and x is an integerwith a value of 20 to 50.

2. A polysilsesquioxane as claimed in claim 1 wherein R istrifluoromethyl.

3. As a composition of matter a polysiloxane having the general formula:

where m is two or three.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,720,644 Dated March 13, 1973 lnv n flw ggpert Neville HASZELDINE andAnthony Edgar TgPPING It is certified that error appears in theabove-identified patent and that said Letters Patent arehereby correctedas shown below:

Abstrect, the first formula reading (R N,-CH -CH S 3.01. 5

should read %(R -N-CH CH S1O x Abstract, the second formula reading-SIL-RO should read Signed and sealed this 26th day of March 1971;.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. G. MAHSI-IALL DANN Attesting OfficerCommissionerof Patents FORM PC4050 (10459) USCOMM-DC 60376-P69 I Q U.5.GOVERNMENT PRINTHG OFFICE: I969 0"365334,

1. As a composition of matter a polysilsesquioxane having the generalformula: ((RF)2-N-CH2-CH2-SiO1.5)x where RF is a fully fluorinated loweralkyl group and x is an integer with a value of 20 to
 50. 2. Apolysilsesquioxane as claimed in claim 1 wherein RF is trifluoromethyl.3. As a composition of matter a polysiloxane having the general formula:( (RF)2N(CH2)mSiRO )Y wherein RF is a fully fluorinated lower alkylgroup, R is a lower alkyl group, m is two or three and y has the value 3to
 16. 4. A polysiloxane as claimed in claim 3 wherein RF istrifluoromethyl.
 5. A polysiloxane as claimed in claim 3 wherein R ismethyl.